This grant is designed to investigate the role of complement and activation of complement via the alternate pathway in the pathogenesis of various skin diseases. We are employing direct immunofluorescent techniques to determine complement staining profile as well as presence of alternate pathway components in herpes gestationis, bullous pemphigoid, pemphigus, circatrical pemphigoid, systemic lupus erythematosus and dermatitis herpetiformis. In vitro studies are being employed to determine activation of complement by pemphigoid antibody and attempts are being made to characterize the "Hg factor" in herpes gestationis. We are also attempting to determine if the IgA deposition in dermatitis herpetiformis has anti gluten activity and if IgA anti gluten antibodies can be detected in sera of these patients. The extent of immunoglobulin and complement skin deposition in systemic lupus erythematosus is being evaluated with regards to presence or absence of lupus skin disease, anti DNA, anti RNA antibodies, renal and central nervous system disease.